Determination of 90 Sr in urine samples and 89 Sr/ 90 Sr in water samples by chemical separation and Cherenkov counting with LSC system

In order to determine radiostrontium with a satisfactory chemical yield, calculated by an external standard, and a low level of MDC a radioanalytical method has been optimized, for environmental and biological samples. Samples were mineralized and extracted by chromatography with prepackaged columns for Cherenkov effect measurement, via daughter radionuclide 90Y, generated by 90Sr. When also 89Sr is present, 90Y is eluted by the same column to subtract its contribution to total Cherenkov counts and determine separately 89Sr and 90Sr (via 90Y) activity. By a fitting experimental data with an exponential equation the eventual presence of other β-emitter radionuclides was ascertained.